diff --git a/.github/workflows/build_and_health_check.yml b/.github/workflows/build_and_health_check.yml
index 8ef1c49..9991fe0 100644
--- a/.github/workflows/build_and_health_check.yml
+++ b/.github/workflows/build_and_health_check.yml
@@ -24,15 +24,22 @@ jobs:
         with:
           java-version: '21'
           distribution: 'temurin'
-          cache: gradle
+
+      - name: setup gradle
+        uses: gradle/actions/setup-gradle@v5
 
       - name: configure 1password
+        id: op-config
         uses: 1password/load-secrets-action/configure@v2
+        continue-on-error: true
         with:
           service-account-token: ${{ secrets.OP_SERVICE_ACCOUNT_TOKEN }}
 
       - name: load secrets
+        id: op-load
         uses: 1password/load-secrets-action@v2
+        continue-on-error: true
+        if: steps.op-config.outcome == 'success'
         with:
           export-env: true
           unset-previous: false
@@ -40,7 +47,12 @@ jobs:
           ENV_FILE: op://instance/.env/.env
 
       - name: create env file
-        run: echo "${{ env.ENV_FILE }}" > .env
+        run: |
+          if [ -n "${{ env.ENV_FILE }}" ]; then
+            echo "${{ env.ENV_FILE }}" > .env
+          else
+            echo "# Empty .env file for tests" > .env
+          fi
 
       - name: run tests
         run: ./gradlew test
@@ -66,7 +78,9 @@ jobs:
         with:
           java-version: '21'
           distribution: 'temurin'
-          cache: gradle
+
+      - name: setup gradle
+        uses: gradle/actions/setup-gradle@v5
 
       - name: configure 1password
         uses: 1password/load-secrets-action/configure@v2
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
new file mode 100644
index 0000000..148490e
--- /dev/null
+++ b/.github/workflows/coverage.yml
@@ -0,0 +1,96 @@
+name: Code Coverage
+
+on:
+  pull_request:
+    branches:
+      - '**'
+  push:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  coverage:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout code
+        uses: actions/checkout@v4
+
+      - name: setup java 21
+        uses: actions/setup-java@v4
+        with:
+          java-version: '21'
+          distribution: 'temurin'
+
+      - name: setup gradle
+        uses: gradle/actions/setup-gradle@v5
+
+      - name: configure 1password
+        id: op-config
+        uses: 1password/load-secrets-action/configure@v2
+        continue-on-error: true
+        with:
+          service-account-token: ${{ secrets.OP_SERVICE_ACCOUNT_TOKEN }}
+
+      - name: load secrets
+        id: op-load
+        uses: 1password/load-secrets-action@v2
+        continue-on-error: true
+        if: steps.op-config.outcome == 'success'
+        with:
+          export-env: true
+          unset-previous: false
+        env:
+          ENV_FILE: op://instance/.env/.env
+
+      - name: create env file
+        run: |
+          if [ -n "${{ env.ENV_FILE }}" ]; then
+            echo "${{ env.ENV_FILE }}" > .env
+          else
+            echo "# Empty .env file for tests" > .env
+          fi
+
+      - name: run tests with coverage
+        run: ./gradlew test jacocoRootReport checkOverallCoverageTarget
+
+      - name: upload coverage report
+        uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: coverage-report
+          path: |
+            **/build/reports/jacoco/
+            build/reports/jacoco/jacocoRootReport/
+
+      - name: add coverage pr comment
+        uses: madrapps/jacoco-report@v1.6.1
+        if: github.event_name == 'pull_request'
+        with:
+          paths: |
+            ${{ github.workspace }}/build/reports/jacoco/jacocoRootReport/jacocoRootReport.xml
+          token: ${{ secrets.GITHUB_TOKEN }}
+          min-coverage-overall: 75
+          min-coverage-changed-files: 70
+          title: 'Code Coverage Report'
+          update-comment: true
+
+      - name: generate coverage badge
+        uses: cicirello/jacoco-badge-generator@v2
+        if: github.ref == 'refs/heads/main'
+        with:
+          jacoco-csv-file: build/reports/jacoco/jacocoRootReport/jacocoRootReport.csv
+          badges-directory: .github/badges
+          generate-branches-badge: true
+          generate-summary: true
+
+      - name: commit and push badge
+        if: github.ref == 'refs/heads/main'
+        run: |
+          git config --local user.email "github-actions[bot]@users.noreply.github.com"
+          git config --local user.name "github-actions[bot]"
+          git add .github/badges
+          git diff --quiet && git diff --staged --quiet || (git commit -m "docs: update coverage badge [skip ci]" && git push)
diff --git a/CLAUDE.md b/CLAUDE.md
index a53f68e..2f1390a 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -47,6 +47,34 @@ docker-compose up -d
 ./gradlew test --tests "*.NormalProfanityFilterTest"
 ```
 
+### 코드 커버리지
+```bash
+# 전체 프로젝트 커버리지 리포트 생성 (모듈별 + 통합)
+./gradlew test jacocoRootReport checkOverallCoverageTarget
+
+# 특정 모듈 커버리지 리포트 생성
+./gradlew :profanity-api:jacocoTestReport
+./gradlew :profanity-domain:jacocoTestReport
+
+# 모듈별 커버리지 목표치 확인
+./gradlew :profanity-api:checkCoverageTargets
+./gradlew :profanity-domain:checkCoverageTargets
+
+# 커버리지 리포트 위치
+# - 통합 리포트: build/reports/jacoco/jacocoRootReport/html/index.html
+# - 모듈별 리포트: {module}/build/reports/jacoco/test/html/index.html
+```
+
+#### 커버리지 목표치
+- **profanity-api**: 70% (Line), 65% (Branch), 70% (Instruction)
+- **profanity-domain**: 80% (Line), 75% (Branch), 80% (Instruction)
+- **profanity-shared**: 60% (Line), 55% (Branch), 60% (Instruction)
+- **profanity-storage:rdb**: 70% (Line), 65% (Branch), 70% (Instruction)
+- **profanity-storage:redis**: 70% (Line), 65% (Branch), 70% (Instruction)
+- **전체 프로젝트**: 75% (Line), 70% (Branch), 75% (Instruction)
+
+*참고: 목표치는 현재 빌드 실패를 유발하지 않으며, 달성 여부만 체크합니다.*
+
 ### 의존성 관리
 ```bash
 # 의존성 확인
diff --git a/README.md b/README.md
index 4f1e8b7..ca086c4 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,9 @@
 
 # 한국어 비속어 필터 API 서비스
 
+[![Coverage](.github/badges/jacoco.svg)](https://github.com/Whale0928/profanity-filter-api/actions/workflows/coverage.yml)
+[![Branches](.github/badges/branches.svg)](https://github.com/Whale0928/profanity-filter-api/actions/workflows/coverage.yml)
+
 > API 인증 키 발급 후 사용 가능합니다. 문서 링크를 참조해 주세요
 >
 >  [API DOCS](https://whale0928.github.io/profanity-filter-api/)
diff --git a/build.gradle b/build.gradle
index f42f0b2..cf6a1f3 100644
--- a/build.gradle
+++ b/build.gradle
@@ -2,6 +2,7 @@ plugins {
     id 'java'
     id 'org.springframework.boot' version '3.4.0'
     id 'io.spring.dependency-management' version '1.1.6'
+    id 'jacoco'
 }
 
 configurations {
@@ -28,6 +29,7 @@ subprojects {
     apply plugin: 'java-library'
     apply plugin: 'org.springframework.boot'
     apply plugin: 'io.spring.dependency-management'
+    apply plugin: 'jacoco'
 
     dependencies {
         // default spring boot dependencies
@@ -54,6 +56,11 @@ subprojects {
     jar.enabled = true
     tasks.named('test') { useJUnitPlatform() }
 
+    // JaCoCo configuration
+    jacoco {
+        toolVersion = "0.8.11"
+    }
+
     test {
         outputs.upToDateWhen { false }
         useJUnitPlatform()
@@ -65,11 +72,198 @@ subprojects {
             showCauses = true
             showStackTraces = true
         }
+        finalizedBy jacocoTestReport
+    }
+
+    jacocoTestReport {
+        dependsOn test
+        reports {
+            xml.required = true
+            html.required = true
+            csv.required = false
+        }
+
+        afterEvaluate {
+            classDirectories.setFrom(files(classDirectories.files.collect {
+                fileTree(dir: it, exclude: [
+                    '**/config/**',
+                    '**/entity/**',
+                    '**/dto/**',
+                    '**/*Application.class'
+                ])
+            }))
+        }
+    }
+
+    // Define coverage targets for each module
+    ext {
+        coverageTargets = [
+            'profanity-api': [
+                line: 0.70,
+                branch: 0.65,
+                instruction: 0.70
+            ],
+            'profanity-domain': [
+                line: 0.80,
+                branch: 0.75,
+                instruction: 0.80
+            ],
+            'profanity-shared': [
+                line: 0.60,
+                branch: 0.55,
+                instruction: 0.60
+            ],
+            'rdb': [
+                line: 0.70,
+                branch: 0.65,
+                instruction: 0.70
+            ],
+            'redis': [
+                line: 0.70,
+                branch: 0.65,
+                instruction: 0.70
+            ]
+        ]
+    }
+
+    // Task to check coverage targets (without enforcing)
+    tasks.register('checkCoverageTargets') {
+        dependsOn jacocoTestReport
+        doLast {
+            def reportFile = file("${buildDir}/reports/jacoco/test/jacocoTestReport.xml")
+            if (reportFile.exists()) {
+                try {
+                    def parser = new XmlParser()
+                    parser.setFeature("http://apache.org/xml/features/disallow-doctype-decl", false)
+                    parser.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false)
+                    def report = parser.parse(reportFile)
+
+                    def moduleName = project.name
+                    def targets = project.coverageTargets[moduleName]
+
+                    if (targets != null) {
+                        def counters = report.counter
+                        def lineCoverage = getCoverage(counters, 'LINE')
+                        def branchCoverage = getCoverage(counters, 'BRANCH')
+                        def instructionCoverage = getCoverage(counters, 'INSTRUCTION')
+
+                        println "\n=========================================="
+                        println "📊 Coverage Report for ${moduleName}"
+                        println "=========================================="
+                        println "Line Coverage:        ${String.format('%.2f%%', lineCoverage * 100)} (Target: ${String.format('%.0f%%', targets.line * 100)}) ${lineCoverage >= targets.line ? '✅' : '❌'}"
+                        println "Branch Coverage:      ${String.format('%.2f%%', branchCoverage * 100)} (Target: ${String.format('%.0f%%', targets.branch * 100)}) ${branchCoverage >= targets.branch ? '✅' : '❌'}"
+                        println "Instruction Coverage: ${String.format('%.2f%%', instructionCoverage * 100)} (Target: ${String.format('%.0f%%', targets.instruction * 100)}) ${instructionCoverage >= targets.instruction ? '✅' : '❌'}"
+                        println "==========================================\n"
+                    }
+                } catch (Exception e) {
+                    println "⚠️  Warning: Could not parse coverage report for ${project.name}: ${e.message}"
+                }
+            } else {
+                println "⚠️  Warning: Coverage report not found for ${project.name}"
+            }
+        }
     }
 }
 
+// Helper function to calculate coverage
+def getCoverage(counters, type) {
+    def counter = counters.find { it.'@type' == type }
+    if (counter != null) {
+        def missed = counter.'@missed'.toInteger()
+        def covered = counter.'@covered'.toInteger()
+        def total = missed + covered
+        return total > 0 ? covered / total : 0.0
+    }
+    return 0.0
+}
+
 // Root 프로젝트의 test task를 수정
 test.dependsOn subprojects.test
 
+// Unified coverage report for all modules
+tasks.register('jacocoRootReport', JacocoReport) {
+    description = 'Generates an aggregate report from all subprojects'
+    group = 'Reporting'
+
+    reports {
+        xml.required = true
+        html.required = true
+        csv.required = true
+    }
+
+    doLast {
+        println "\n=========================================="
+        println "📊 Unified Coverage Report Generated"
+        println "=========================================="
+        println "HTML Report: ${reports.html.outputLocation.get()}/index.html"
+        println "XML Report:  ${reports.xml.outputLocation.get()}"
+        println "==========================================\n"
+    }
+}
+
+project.afterEvaluate {
+    tasks.named('jacocoRootReport').configure {
+        // Explicit dependencies on all test and jacocoTestReport tasks
+        dependsOn test  // Root project test task
+        dependsOn subprojects.test
+        dependsOn subprojects.jacocoTestReport
+
+        additionalSourceDirs.setFrom files(subprojects.sourceSets.main.allSource.srcDirs)
+        sourceDirectories.setFrom files(subprojects.sourceSets.main.allSource.srcDirs)
+
+        def allClassDirs = files(subprojects.sourceSets.main.output).files.collect {
+            fileTree(dir: it, exclude: [
+                '**/config/**',
+                '**/entity/**',
+                '**/dto/**',
+                '**/*Application.class'
+            ])
+        }
+        classDirectories.setFrom files(allClassDirs)
+
+        executionData.setFrom project.fileTree(dir: '.', include: '**/build/jacoco/test.exec')
+    }
+}
+
+// Task to check overall coverage target
+tasks.register('checkOverallCoverageTarget') {
+    dependsOn jacocoRootReport
+    doLast {
+        def reportFile = file("${buildDir}/reports/jacoco/jacocoRootReport/jacocoRootReport.xml")
+        if (reportFile.exists()) {
+            try {
+                def parser = new XmlParser()
+                parser.setFeature("http://apache.org/xml/features/disallow-doctype-decl", false)
+                parser.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false)
+                def report = parser.parse(reportFile)
+
+                def counters = report.counter
+                def lineCoverage = getCoverage(counters, 'LINE')
+                def branchCoverage = getCoverage(counters, 'BRANCH')
+                def instructionCoverage = getCoverage(counters, 'INSTRUCTION')
+
+                // Overall project targets
+                def overallTargets = [
+                    line: 0.75,
+                    branch: 0.70,
+                    instruction: 0.75
+                ]
+
+                println "\n=========================================="
+                println "🎯 Overall Project Coverage Report"
+                println "=========================================="
+                println "Line Coverage:        ${String.format('%.2f%%', lineCoverage * 100)} (Target: ${String.format('%.0f%%', overallTargets.line * 100)}) ${lineCoverage >= overallTargets.line ? '✅' : '❌'}"
+                println "Branch Coverage:      ${String.format('%.2f%%', branchCoverage * 100)} (Target: ${String.format('%.0f%%', overallTargets.branch * 100)}) ${branchCoverage >= overallTargets.branch ? '✅' : '❌'}"
+                println "Instruction Coverage: ${String.format('%.2f%%', instructionCoverage * 100)} (Target: ${String.format('%.0f%%', overallTargets.instruction * 100)}) ${instructionCoverage >= overallTargets.instruction ? '✅' : '❌'}"
+                println "==========================================\n"
+            } catch (Exception e) {
+                println "⚠️  Warning: Could not parse overall coverage report: ${e.message}"
+            }
+        } else {
+            println "⚠️  Warning: Overall coverage report not found"
+        }
+    }
+}
+
 bootJar.enabled = false
 jar.enabled = true